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Applied Surface Science,
274:378-391
2013
Resume: Interaction of discharges in heptane with magnetron-sputtered thin films made of aluminum, copper or iron is studied in a pin-to-plate configuration. The behavior of discharges on thin films can be used to better understand the interaction of discharges with given surfaces and it might also improve the reproducibility of the impacts in order to better control their shape. Single layers and bilayers of metals are characterized after impact by SEM, AFM, micro-EDX and nano-SIMS analyses. Discharges last typically for a few hundreds of nanoseconds and dissipated energies range between 1 and 100 mJ. We show that at low impact energy, copper and aluminum are heated and stretched by surface stress. At intermediate energy, melting occurs, leading to the synthesis of external beads by Marangoniâ??s convection. At high energy, the shape of the impact is defined by the pressure release when the discharge stops. When iron is deposited onto silicon, dewetting is an important mechanism. The columnar structure of the deposit may have two distinct roles. On the one hand, gases trapped in intercolumnar boundaries can produce tiny holes. On the other hand, the shock wave can abrade the outermost and less cohesive part of the film if it is made of columns separated by large porosities. Equipe: Département CP2S : Expériences et Simulations des Plasmas Réactifs - Interaction plasma-surface et Traitement des Surfaces ESPRITS |
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Materials Science Forum,
738-739:97-102
2013
Resume: proceedings Conférence ESOMAT 2012 Equipe: Département SI2M : Microstructures et Contraintes |
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Matériaux et Techniques,
101:204
2013
Equipe: Département CP2S : Expériences et Simulations des Plasmas Réactifs - Interaction plasma-surface et Traitement des Surfaces ESPRITS |
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Journal of Materials Chemistry C,
1(42):6930-6934
2013
Equipe: Département P2M : Nanomagnétisme et Electronique de Spin |
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Journal of Applied Physics,
114(16)
2013
Equipe: Département P2M : Nanomagnétisme et Electronique de Spin |
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APPLIED SURFACE SCIENCE,
267:21-25
2013
ISSN: 0169-4332
Equipe: Département P2M : Surfaces et Spectroscopies |
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Revue de Métallurgie,
110(04):297--305
2013
Equipe: Centre de Compétences : Matériaux et Procédés additifs |
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Nuclear Fusion,
53:104003
2013
Equipe: Département CP2S : Expériences et Simulations des Plasmas Réactifs - Interaction plasma-surface et Traitement des Surfaces ESPRITS |
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Material Science and Engineering A,
561:477--485
2013
Equipe: Département SI2M : Microstructures et Contraintes |
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Journal of Applied Physics,
113:213303
2013
Resume: The main processes related to discharges between pin and plate electrodes in hydrocarbon liquid (heptane) are modelled for micro-gap (from 10 to 100 mu m) conditions. When a plasma channel hits the surface, a micro-crater is created. The different phenomena controlling the geometry (shape and dimension) of a single crater are described and included in a theoretical model developed for the specific case of pure aluminium. The influence of the most important parameters affecting the geometry of the crater is discussed. Among them, one finds the pressure exerted by the plasma on the liquid metal. It is found that the distribution of the pressure applied on the liquid pool changes significantly the way the plasma shapes the pool. It is assumed that at high charges, the pressure profile is tilted from the channel axis, leading to the formation of a central protrusion. On the other hand, we demonstrate that Thomson-Marangoni forces play an important role for crater diameters smaller than 5 mu m. Then, the choice of the first derivative of the surface tension with respect to the temperature is a key factor. This effect is strongly related to the way convection displaces matter in the liquid pool. Finally, the quenching step is sufficiently fast to freeze the liquid shape as soon as the plasma vanishes. (C) 2013 AIP Publishing LLC. Equipe: Département CP2S : Expériences et Simulations des Plasmas Réactifs - Interaction plasma-surface et Traitement des Surfaces ESPRITS |